Antioxidant or age-retarder



Patented Jan. 12, 1932 JAN TEPPEMA,

ire!) srA rss 015 AKRON,'OHIO, ASSIGNOR ro rrfingeoonxnnn TIRE &-RuB1i:n-'CoM- IPANY, F AKRON, QHI fAcQRg 03.9310 1 An'rIoxInAnr 03 AGE-RETARDER No Drawing.

This invention relatesto methods of treating rubber, transformer oils, soapsand similar organic materials, and it has particular relation to processes of preserving such compounds." I

One object of the invention is to provide an antioxidant 'orgpreservative of organic compounds which does: notst-ain or discolorthe materials into which it is introduced, upon exposure to atmospheric conditions;

Heretofor'e, it has been observed that upon being ex osed to atmospheric conditions,

rubber goods, transformer oils, soaps and similar organic compounds absorb oxygen from the air, thus resulting in hardening of color changes, thereby imparting undesirable Y stains to the goods into which they are intro& duced. 5

This invention consists in the discovery that certain naphthols, notably the di-naphthols, are quite eflicient as antioxidants or preservatives of organic compounds, and do not appreciablystain the compounds upon exposure to the atmospheric conditions.

One notable example of a compoundof this class is methylene di-beta-naphtholwhich may be prepared by causing two molecular proportions of beta-nap'hthol to'react with formaldehyde in the presence of a condensing agent, like soduim acetate. This method is discussed in detail in Berichte, vol. '39, page 439.

The reaction occurring may be repreapplicationfiled' n vemtei zs, 192s. Serial No. aaaos 'r."

sented by the 2 structural forfinula i This beemployed with sat 'isfactoryresult's in most of; .the standard rubber. formulae, as well as intransformer I r oils,..soaps and various other organic 'materialswhich it maybe desirable to; preserve from oxidation. The compound isiparticularly useful in such rubber/goods of light Y color, as flooring tiles in which it ishighly desirableto obtain a productthat isnot appreciably affected by long exposure to air and light and which is notdiscolored by these agencies. The following isw n example of a formulaflwhich may be employed to manufacture rubber tiles with excellent results:

Pale crepe rubber Q 20.00 parts Sulphur 200 parts L1me Q 1. 00'part Magnesia 4. 00 parts Ground clay 72.60 parts Stearic acid; 1. parts Methylene di-beta naphthol .40 part Of course, it is to be u'nderstoodthatthe above proportions are merely exemplary,

and relatively wide departure may be made from the exact prop'ortionsgiven without creating. agreatchange in Qt-he character of the product. I

To test the efficiency of the new material as an antioxidant, 'control samples' of material containing no antioxidant and also similar samples of material containing from one to two p ercent of methylene di beta-naphthol were placed in an oxygen bomb, and were maintainedata temperature of 50 (3.; undera pressure of pounds persquare inch oxygen'pressurefor aperiod of six days. At the end ofthistime, itwas found that the control samples containing no antioxidant were severely OXlCllZeCl to a depth of approximately 9 of an inch. This oxidized surface coating was relatively brittle and practically devoid of elasticity, so that it broke upon slight fleXure. On the other hand, samples of material containing methylene di-beta-naphthol as a preservative were in practically as good condition physically as when placed in the bomb. Also, the color of the tiles was but slightly changed during the prolonged period of artificial aging. In order further to test the permanency of the color of the product, samples of tiles containv ing the new antioxidants were subjected to the action of sunlight for several weeks. The

color of the samples was substantially un,.

changed by this treatment. Under similar conditions, samples ofrubber containing antioxidants heretofore known are so stained by the action of the oxygen upon the antioxidant that they are unfit for commercial use.

Although only methylene di-naphthols have been discussed in detail, many other compounds of the same general class have similar antioxidant properties and may be substituted therefor in the usual rubber formulae. 'Butyraldehyde, 'crotonaldehyde, acetaldehyde and benzaldehyde have all been reacted with naphthols, for example beta-naphthol, and the reaction products have in each instance been found to possess antioxidant properties.

Although I have described in detail only one embodiment of the invention, it will be apparent to those skilled in the art that it is not so limited but that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What I claim is:

1. A method of preserving organic compounds which comprises introducing therein a substance having the formula OH HO R CHz -R1 in which R and R are naphthalene groups.

2. A method of preserving organic compounds which comprises introducing therein a reaction product of naphthol and an aldehyde. r p

3. A method of preserving rubber which comprises vulcanizing it in the presence of a material having the structural formula on no in which R and groups."

Rl R represents naphthalene comprises subjecting it to vulcanization in the presence of a reaction product of betanaphthol and formaldehyde.

6. A method of preserving rubber which comprises subjecting it to vulcanization in the presence of methylene di-beta-naphthol.

7. A method of preserving rubber which comprises subjecting it to vulcanization in the presence of an alkylidene di-naphthol.

8. A rubber product that has been vulcanized in the presence of a material having the following structural formula:

- OH HO in which R and B represent naphthalene groups. 7 9. A rubber product that has been vulcanized ,inthe presence of a reaction product of a napht-hol and an aldehyde.

the presence of a material having the formula on HO where R and R are naphthalene groups and. X is an aliphatic hydrocarbon residue, saidinaterial being. substantially a non-accelerator of vulcanization;

15; A rubber product that has been vulcanized in the presence of a material having the formula on HO wherein R and R are naphthalene groups and X is an aliphatic residue. 1 In witness whereof, I have hereunto signed 'my name. v

Signed at Akron, in the county of Summit and'State of Ohio, U. S. A., this 23rd day of November, 1928.

. JAN TEPPEMA.

4. A method ,of preserving rubber which comprises incorporating therein a reaction product of a naphthol and formaldehyde.

5. A method of preserving rubber which 

